Conventional methods of drying laundry articles involve tumbling the articles in a drum whilst a warm airstream is passed therethrough. The water trapped in the articles evaporates into the warm airstream and is carried out of the drum therewith. The water vapour is either released into the atmosphere or condensed out of the airstream and collected to be drained off. Conventional methods of drying articles in a dishwasher device also involve passing heated air over the articles to cause evaporation of the water lying on the articles and removing the water vapour with the airstream. The disadvantages of these methods include the fact that the articles to be dried are often subjected to high temperatures if a particularly fast drying time is required. In the case of clothes dryers, this can damage the fabric and, in the case of dishwashers, the crockery becomes too hot to handle as soon as the washing and drying cycle has finished.
It is a well known principle that water will boil at a temperature lower than 100° C. if the pressure in the vessel in which it is contained is reduced below atmospheric. Proposals for drying laundry articles based on this principle have been put forward but, to date, none has been found to be sufficiently effective to form the basis for a commercially-viable drying apparatus. The principal reason for this is that the vacuum pump by means of which the chamber containing the articles to be dried is evacuated is required to deliver very high flow rates, in order to be able to evacuate the evaporating water vapour, and to develop a high pressure drop thereacross. Such components, whilst available on the market, are prohibitively expensive for use in the context of domestic apparatus.